Food composition and process of inhibiting oxygenation thereof



Patented July 12, 1938 UNITED STATES roon oomosrrron AND raocns's or 1N-mm'rmc OXYGENATION 'rnanaor Harvey D. Royce, Savannah, Ga., assignor toThe Southern Cotton Oil Company, New Orleans, La., a corporation of NewJersey No- Drawing. Application July 30, 1936, Serial No. 93,525

4 Claims. (Cl. 99-168) My invention relates to food composition andprocess of inhibiting oxygenation thereof and has to do, moreparticularly, with the use of a novel synthetic compound as anantioxidant, that is,

5 an inhibitor of oxygenation, in retarding the development of rancidityor oxidation in fats, oils, fatty compositions, and unsaturated organiccompounds.

It has been the practice, for many years, to. add

1 various antioxidant compounds to fats, oils and unsaturated organiccompounds, to retard the development of rancidity and oxidation, but themost effective antioxidants or inhibitors of rancidity, such as thequinones, polyphenols, naphthols, aromatic amino derivatives, andunsaturated polybasic aliphatic acids, are toxic and undesirable for usein the edible fatty compositions. There is, therefore, a distinct needfor non-toxic and neutral flavored antioxidants, which will en- I hancethe keeping quality of edible fats and fatty foods. without detractingfrom their palatability and digestibility, and the principal objectof myinvention is toprovide a fatty food composition including an oxygenationinhibitor or antioxident of that character.

A further object of my invention is to provide a process for inhibitingoxygenation in food compositions by incorporating therein a syntheticcompound derived from incompletely esterified fatty acid esters ofpolyhydric alcohols, which ess of stabilizing the same.

In general, my invention consists in the inhibiting of oxygenation offood compositions by.

the incorporation therein of new, synthetic, phosphatic, fat-solubleproducts resulting from the treatment of incompletely esterified fattyacid esters of polyhydric alcohols, in successive steps, with phosphoricanhydride and primary aliphatic amino alcohols, which productsconstitute a class my application filed August 4, 1934, Serial No.738,543, for Stabilized food composition and procclassification. Ingeneral, however. the new antioxidants used in my present invention maybe represented by the formula:

in which P is phosphorus, 0 is oxygen, R is hydrogen or an alkyl, group,OY is an aliphatic primary beta amino alkoxy radical linked to P throughits oxygen, X is a polyhydric alcohol group with at least one of the(OH) groups esterified with a fatty acid, andm. is a small whole number.

(1) The following is a specific example of the procedure which I havefollowed in preparing an inhibitor of oxygenation for use in myinvention. ,A substance consisting of a mixture of monoand di-glyceridesof the cottonseed fatty acids, having an acetyl numberof about 170, isprepared by re-esterifying cottonseed oil with one-fourth its weight ofglycerol. This mixture, which I call mono-glyceride concentrate, ismixed with one-fifth its weight of phosphoric acid anhydride at 60 C.,in a dry atmosphere, and the temperature is allowed to rise to 115 C.The product of this reaction is essentially a mixed phosphoricacid-fatty acid ester of glycerol. This mixed ester is then cooled to0., and one-sixth its weight of beta amino ethanol is added slowly, withstirring, keeping the temperature ,below 0. That fraction of the productof this reaction which is fat-soluble, comprises the antioxidant of myinvention, and may be separated from the fat-insoluble residue by benzolextraction and then freed from the solvent by vacuum steam distillation.H

The structure of such an inhibitor or antioxidant prepared frommono-glyceride of cottonseed fatty acids, phosphoric anhydride, and betaamino ethanol would be represented as follows:

onion HOAc 0 HgO-P-O-CHr-CHa-NE in which Ac an acyl group derived fromthe mixed fatty acids of cottonseed, and the remain- I water, giving amilky emulsion. It is partially soluble alcohol. It is wholly soluble inether, chloroform and fixed oils.

I have found that the inhibitor or antioxidant so prepared may be usedeffectively in inhibiting rancidity of edible fats, and oils andunsaturated organic compounds. For instance, in the preservation ofvegetable shortening compound, I dissolved one part of the phosphaticantioxidant, prepared as heretofore described, in 5000 parts of theshortening. The comparative keeping qualities of the treated anduntreated shortening were measured by following the increase in peroxidevalues under accelerated aging conditions. After seven hours aging at100 C. the respective peroxide values for-the control and the treatedshortening were 112 and 34. Moreover, at the end of this test the odorof the control was strongly rancid, whereas the treated sample was sweetand unchanged in odor. In general, I have found that the shelf life" ofcommercial edible fats, oils and fatty foods will be increased from 50to 200 per cent by incorporating therewith from 0.01' to 0.05 per centof the phosphatic antioxidants in-accordance with my present invention.

(2) As a second example of procedure which I have followed in preparingan inhibitor for use in practicing my invention, diglycol stearate wasmixed with one fifth of its weight of phosphoric acid anhydride at 80C., in a dry atmosphere, and the temperature rose to 95 C. during thereaction.v The mixture was then cooled to 60 C. and neutralized withmonoethanolamine. To the resulting product there was added one half its7 weight of ethyl alcohol, whereupon a separation occurred, theantioxidant remaining in solution, and a considerable quantity ofunidentified fatinsoluble material separated out. The alcohol wasdistilled from the antioxidant in a current of steam at reducedpressure, and the antioxidant product was tested foroxygenation-inhibiting strength by adding 0.02 per cent (one part to5000) to salad oil, and the induction period of oxidation of the oil wasfound to be 6 days aging at 63 C. for the treated sample, as comparedwith 2 days for the untreated control sample.

(3) As a third example of procedure followed in preparing such aninhibitor or antioxidant, eighty (80) grams of butyric acid was heatedwith thirty (30) grams of glycol in the presence of 0.05% sodiumcarbonate for two hours in a current of carbon monoxide. To theresulting glycol butyrate ester there was added-thirty (30) grams ofphosphoric acid anhydride, after which the mixture was neutralized withmonoethanolamine, and treated with ethyl alcohol and the antioxidantproduct recovered, as described above as to Example 2. The antioxidantthus obtained was tested as to its strength in inhibiting induction ofoxygenation and rancidity by adding 0.02 per cent by weight to saladoil, and the induction period of oxygenation was found to be 5 days forthe treated sample, as compared with 2 days for the untreated controlsample.

It will thus be seen that the antioxidant can be prepared from fattyacids having four or more carbon atoms, and that I have found thatglycol,

' diglycol or glycerol'may be used, so long as at completely esterifiedfatty acid esters of polyhydric alcohols",'I mean all fatty acid estersof polyhydric alcohols having one or more free unesterified alcoholichydroxyl groups in the molecule. In other words, it is essential to haveat least one free hydroxyl group in the fatty ester which is to betreated with phosphoric acid anhydride, but it is allowable to have morethan one free hydroxyl group. Likewise, it is essential to have at leastone of the alcoholic hydroxyl f groups of the polyhydric alcohol portionof the molecule esterified with a fatty acid, but it is alsoallowable tohave more than one hydroxyl group esterified with a fatty acid.

While, in the foregoing paragraphs, I have mentioned specificallycertain phosphatic, fatsoluble antioxidants, it should be understoodthat my invention is not limited to the use of pure substances, orcompositions containing these particular substances, but-includescompositions containing as fat antioxidants various other substancesfalling within the broad scope of my invention. However, I do not intendto include as within my invention the use of natural phospholipids.While the structures of certain of the synthetic antioxidants preparedin accordance with my invention are much like those of the naturallyoccurring phospholipids, these synthetic antioxidants are distinguishedfrom the natural phospholipids by the following properties:

(a) Greater solubility in water. The natural phospholipids swell in thepresence of water, but do not form a true solution, whereas thesynthetic antioxidants of my invention dissolve readily in water andform a true solution.

(b) Absence of optical activity. The synthetic inhibitors have nooptical activity, that is, do not rotate the plane of polarized light,whereas natural phospholipids rotate the plane of polarized light.

(0) Higher antioxidant index. For the purposes of this specification, Iwill define the antioxidant index as the degree of protection againstrancidity conferred upon cottonseed oil by the Peroxide value ofuntreated oil Peroxide value of treated oil For instance, referring tothe preceding paragraph (Example 1), in which I described the resultsattained by mixing a small percentage of antioxidant with shortening,the specific antioxidant index, using the figures there given, would be=antioxidant index.

(11) Higher phosphorus content. The phosphorus content of the syntheticantioxidant prepared according to the specific example given above willbe approximately 4%, which is considerably higher than in naturalphospholipids.

eral formula:

o x[-o-i oRl h in which P is phosphorus, 0 is oxygen, R is hydrogen oran alkyl group, OY is a beta amino ethanol radical linked to P throughits oxygen, X is a radical of a polyhydric alcohol selected from thegroup consisting of glycerol and diglycol in which at least one OH groupis esterifled with a fatty acid having at least four carbon atoms and atleast one OH group is not esterifled, and n is "a small whole number.

2. A food composition having improved keeping qualities comprising anedible fat having incorporated therein a small amount of a synthetic.fat-soluble antioxidant represented by the formula:

onion H0 Ac 0 11,-0- on OOHr CEa-NH: in which Ac is an acyl groupderived from a fatty CERTIFICATE OF Patent No. 2,1 5,865

acid having at least Iour carbon atoms, and the remaining terms havetheir customary chemical significance.

3. The process of inhibiting the inception of oxygenation of fatty foodcompositions, which comprises mixing therewith a small amount of anincompletely esterifled, fat-soluble mixed phosphoric acid fatty acidester of a polyhydric alcohe], represented by the formula:

CHQOH HO-Ac 0 Hz-O- OH CHrCHg-NH;

in which Ac is an acyl group derived from a fatty acid having at leastfour carbon atoms, and the remaining terms have their customary chemicalsignificance.

4. The process of inhibiting the inception of oxygenation of fatty foodcompositions which comprises admixture therewith of a small amount of anincompletely esterifled fat-soluble mixed phosphoric acid-fatty acidester represented by the general formula:

in which P is phosphorus, O is oxygen, R is 9. meta amino ethanolradical linked to P through its oiwgen, X is a radical of a polyhydricalcohol selected from the group consisting of glycerol and diglycol inwhich at least one OH group is esterified with a fatty acid having atleast four carbon atoms and at least one OH group is not esterifled, andn is a small whole number.

HARVEY D. ROYCE.

CORRECTION.

July 12, 19

HARVEY D. ROYCE.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 5,second column, line 51, claim 1 for "meta" read beta;

and that the said Letters Patent should be read withthis correctiontherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this th day of August, A. D. 1958.

( Seal) IIenryVan Arsdale Acting Commissioner of Patents.

